The overall objective of our total research program is to identify and characterize the genetic and biochemical properties of the regulatory mechanisms that control the biosynthesis and biological acvitivies of eukaryotic interferons. Our goals set for the next year include: Expanding and extending our on going studies on the regulation of the establishment and maintenance of the antiviral state in chick embryo cells to include human cell lines containing variable numbers of chromosome 21. Examining primary viral transcriptional and translational events in our mutant virus-resistant mouse cells. Obtaining virus-resistant mutants of human cell lines.